Automatic cable retracting system

ABSTRACT

An automatic cable retracting system includes a base and a guide connected to the base, the guide translationally movable along a line parallel to the surface of the base. A biasing device is provided for resisting movement of the guide, in a direction along the line, over a range of motion. A cable having a middle section and a first and second end of the middle section is provided, a portion of the middle section being in contact with and changing direction around the guide. The system can be configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion. The system can further be configured so that the length moved by the first end as a result of the tension is greater than the distance moved by the guide as a result of the tension. The system may be integrated into an electronic device, such as a speaker, a computer mouse, a keyboard or the like.

BACKGROUND OF THE INVENTION

Automatic cable winding mechanisms are typically circular devices and tend to be one of two standard construction approaches.

In a first approach, a circular winding mechanism is installed in the center of a cable and spring-loaded so that as the cable is extended, equal amounts of cable are released from each end. During the extension, the spring is tensioned in a manner that is contrary to the motion of the cable so that its natural tendency is to retract the cable if the ends are released. This type of mechanism has a disadvantage in that the mechanism needs to be installed in the middle of the cable. Thus, for every inch of cable released in one direction, an equal amount of cable is released in the opposite direction, which, among other things, makes this solution unsuitable for installation inside a product.

In a second approach, a circular winding mechanism is constructed so that one end of the cable remains fixed to the spool around which the cable is wound. The cable is then wound around the spool, with the spool spring-loaded such that as the cable is extended, cable is released from the spool and the tension on the spring increases so that the natural tendency of the spring is to reverse the action of the spool and thereby wind the cable back up if the end is released. Electrical connection of the moving (rotating) cable at the end that is affixed to the spool is accomplished with circular contacts and metal brushes or wipers which contact metal rings and carry the electrical signals to the rest of the system. Using this type of mechanism, the cable may be extended in one direction away from the spool without additional cable being released in the opposite direction. Thus, this mechanism may be mounted internally to a product, but cannot effectively be used in the middle of a cable. A major disadvantage of this approach is that moving electrical contacts (wipers or brushes) generate electrical noise, which typically increases over time as the contacts wear.

SUMMARY OF THE INVENTION

There is a need for an automatic cable retracting system that avoids one or more limitations associated with the prior art. The present invention aims to solve at least one of these and other limitations.

According to one embodiment of the invention, an automatic cable retracting system includes: a base and a guide connected to the base, the guide being translationally movable along a line parallel to a surface of the base. A biasing device is provided for resisting movement of the guide, in the direction along the line, over a range of motion. A cable having a middle section and a first and second end of the middle section is further provided, a portion of the middle section being in contact with and changing direction around the guide. The system is configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion, the length moved by the first end as a result of the tension being greater than the distance moved by the guide as a result of the tension. In this embodiment, the cable is not permanently affixed to the base.

According to another embodiment, an automatic cable retracting system of the invention includes: a base; guides connected to the base, the guides being translationally movable along a direction relative to the base. A biasing device is provided for resisting movement of at least one guide, in the direction, over a range of motion. A cable having a middle section and a first and second end of the middle section is provided, a portion of the middle section being in contact with and changing direction around at least one guide. The system is configured so that a tension on the first end causes the first end to move a length, and causes the at least one guide to move a distance of at least a portion of the range of motion, such that the length moved by the first end as a result of the tension is greater than the distance moved by at least one of the guides as a result of the tension.

According to a further embodiment, an automatic cable retracting system includes a housing and a guide connected to the housing, the guide being translationally movable along a direction relative to the housing. A biasing device is provided for resisting movement of the guide, along the direction, over a range of motion. A cable having a middle section and a first and second end of the middle section is provided, a portion of the middle section being in contact with and changing direction around the guide. The system is configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion, the length moved by the first end as a result of the tension being greater than the distance moved by the guide as a result of the tension. A single wall of the housing has a track along which the guide is movable.

According to a further embodiment, an automatic cable retracting system includes a housing and a guide connected to the housing, the guide being translationally movable along a direction relative to the housing. A biasing device is provided for resisting movement of the guide, along the direction, over a range of motion. An electric cable having a middle section and a first and second end of the middle section is provided, a portion of the middle section being in contact with and changing direction around the guide. The system is configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion. The length moved by the first end as a result of the tension is greater than the distance moved by the guide as a result of the tension, and all portions of the electric cable within the housing are substantially coplanar.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of at least one embodiment of the invention.

In the drawings:

FIG. 1 shows a perspective view of an automatic cable retracting system according to an embodiment of the invention.

FIG. 2 shows a side view of an automatic cable retracting system according to an embodiment of the invention.

FIG. 3 shows a perspective view of an electronic device (e.g., a speaker) having an automatic cable retracting system according to an embodiment of the invention.

FIG. 4 shows a perspective view of a partially extended extension cord utilizing an automatic cable retracting system according to an embodiment of the invention.

FIG. 5 shows a schematic view of a mouse utilizing an automatic cable retracting system according to an embodiment of the invention.

FIG. 6 shows a schematic view of a keyboard utilizing an automatic cable retracting system according to an embodiment of the invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Turning first to FIG. 1, an embodiment of a cable retractor 2 is shown. The cable retractor 2 comprises a base 4, guide 8 rotatably mounted on the base 4, guides 10, 12 rotatably mounted on a sliding plate 14, the sliding plate 14 being slidably mounted on the base 4 via a track 18, apertures 26, 28, and a biasing device 20 biasing the sliding plate 14 away from the apertures 26, 28. A cable segment 6 has first and second portions 22, 24, each of the first and second portions having a stop 30, 32 respectively. The stops 30, 32 prevent the cable segment 6, excluding first and second portions 22, 24, from passing through the apertures 26, 28. The cable retractor 2 is assembled for use by having the cable segment 6 threaded through aperture 26, around guide 12, around guide 8, around guide 10, and through aperture 28 such that the stops 30, 32 are located on the side of the apertures 26, 28 away from the guides 10 and 12.

In operation, a tension may be applied to the cable segment 6 pulling one portion 22 (or 24) in a direction a, causing the portion 22 (or 24) of the cable segment 6 to move a length, and thereby causing the sliding plate 14 to move a distance in the direction a that is less than such length. The movement of sliding plate 14 is against the bias of the biasing device 20. As the portion 22 (or 24) is pulled, cable segment 6 moves relative to the base 4 and relative to guides 8, 10, 12, which are embodied in FIG. 1 as pulleys comprising wheels rotatable relative to the base 4. The portion 22 (or 24) may be pulled a maximum distance, corresponding to the full range of motion of the sliding plate 14 and/or biasing device 20. As shown, sliding plate 14 cannot move in direction a beyond the end of track 18, which distance may define the sliding plate's full range of motion. As shown, either or both portions 22, 24 may be pulled from the base 4, causing the sliding plate 14 to move in direction α. In a fully retracted configuration, stops 30, 32 are in contact with their corresponding apertures 26, 28, and the bias of the biasing device 20 prevents slack of first and second portions 22, 24 of cable segment 6.

The base 4 may comprise a printed circuit board, and/or may be one or more wall(s) of a housing. Guides 8, 10, 12 cause a linear medium, such as cable segment 6, to change direction, and may or may not include a rotational element, such as a wheel. In one embodiment, guide 8 comprises a rotatable wheel that is rotatably connected to the base 4, and guides 10, 12 each comprises a rotatable wheel that is rotatably connected to the sliding plate 14, via rotation axes. These rotation axes may comprise ball bearings or other bearing system known in the art, and/or a low-friction material or composition, as understood by one of ordinary skill in the art, to reduce rolling friction as the guides' wheels rotate about the axes. In one embodiment at least one of the guides 8, 10, 12 is not rotatable with respect to the housing 4 or sliding plate 14. For example, guide 8 may comprise a circular wheel-shaped element or guidepin that is permanently fixed and does not rotate with respect to the housing 4. Such a guide may comprise and/or be coated with a low-friction material or composition to reduce friction caused by the cable segment 6 moving along the guide. An advantage to such a feature is simplicity of design and reduction in manufacturing costs.

While the biasing devices are represented thoughout the drawings as springs, it will be understood by those of ordinary skill in the art that any suitable biasing device may be used without departing from the scope of the invention. The biasing device may comprise, e.g., a coil spring, an elastic band, a shock cord, an arm made of flexible metal (such as a memory metal), or any device that absorbs, stores, and releases energy, including a mechanical spring, an electric spring, a magnetic spring, a pneumatic spring, a hydraulic spring, or any mechanism or apparatus that operates as a spring. Any known device that allows sliding plate 14 to by pulled in direction α while absorbing and storing energy is within the scope of the present invention.

Cable segment 6 may comprise an electrical cable, such as a USB cable, an audio cable, a video cable, a network cable, or any cable configured to transfer an electrical signal to or from an electrical device, and/or to transfer electric power to or from an electric device, but, as used herein, the term cable is intended to include a rope, a tube, a fiber optic strand or cable, or any linear medium. In one embodiment, first and second portions 22, 24 of the cable segment 6 pass through apertures 26, 28 that are located along the same edge of the base 4. Alternatively, first and second portions 22, 24 of the cable segment 6 may pass through a single common aperture (not shown). An advantage to this feature is that the total amount of cable that can be retracted by the cable retractor 2 is generally greater than if first and second portions 22, 24 passed through apertures located along different edges of the base 4.

In one embodiment, sliding plate 14 connecting guides 10, 12 is translationally movable in direction α and −α. Biasing device 20 causes the sliding plate 14 to be biased or tensioned in direction −α. The cable segment 6 is in contact with guides 8, 10, 12 in the manner shown in FIG. 1, so that the cable retractor 2 is configured to allow one or both portions 22, 24 of the cable segment 6 (in equal or unequal amounts) to be extended from the apertures 26, 28 against the bias or tension of the biasing device 20. As an amount of a portion 22, 24 of the cable segment 6 is extended from its corresponding aperture 26, 28, the sliding plate 14 moves in direction a against the bias or tension of the biasing device 20, and the cable segment 6 moves relative to the guides 8, 10, 12. If one or more of the guides 8, 10, 12 have rotatable wheels, movement of the cable segment 6 may cause these wheels to rotate about its or their respective axes. In one embodiment, both portions 22, 24 are free to be extended, either one at a time or simultaneously (i.e., neither portion 22, 24 or any portion of the cable segment 6 is permanently affixed to the base 4). In another embodiment, at least one part of a the first or second portion 22, 24 of cable segment 6 is permanently affixed with respect to the base 4 so that only the other one of the first and second portion 22, 24 may be extended from its corresponding aperture 26, 28.

In one embodiment, sliding plate 14 may be slidably attached to the base 4. In another embodiment, sliding plate 14 is not attached in any manner to the base 4. Where sliding plate 14 is slidably attached to the base 4, the sliding plate 14 may comprise one or more bolts or guidepins (not shown), and the track 18 may comprise an elongated opening through which the bolts or guidepins pass, thereby slidably connecting the sliding plate 14 to the base 4. The one or more guidepins may comprise heads having a diameter larger than a width of track 18, and shafts having a diameter smaller than the width of track 18, so that the sliding plate 14 is slidably connected to the base 4. The one or more guidepins and/or track 18 may comprise and/or be coated with a low-friction material or composition to reduce moving friction of the sliding plate 14 along the track 18. The one or more guidepins are merely one possible means of slidably connecting sliding plate 14 to the base 4—other means known in the art are within the scope of the present invention. As another example, track 18 may be sufficiently wide so that sliding plate 14 fits inside of and slides relative to the track 18. As another example, where guides 10, 12 comprise wheels rotatable about axles connected to the sliding plate 14, these axles may extend through the sliding plate and the track 18 to serve as the aforementioned guidepins. As yet another example, where guides 10, 12 are not wheels, but rather take the form of guidepins to guide the cable segment 6, one or both of these guidepins may extend into track 18.ln yet another embodiment, track 18 is entirely omitted, and sliding plate 14 is maintained in a proper position by the competing forces between the tension in the cable segment 6 and the tension in the biasing device 20.

The cable retractor 2 may be configured such that a continuous bias is placed on the cable segment 6 via the sliding plate 14 connected to the biasing device 20, where once the extended portion of the cable segment 6 is released, the cable retractor 2 automatically retracts into the retracted configuration. A user of the cable retractor 2, however, may not want to provide continuous tension on the extended portion of the cable segment 6 throughout use of the cable retractor 2. Thus, in another embodiment, the cable retractor 2 comprises a lock (not shown) that allows the cable segment 6 to be locked in one or more extended configuration. For example, the lock may comprise a simple friction lock of any suitable type known in the art, such as those used in conventional tape measures, in which the tape may be drawn from the source to a desired length and manually or automatically locked in place by friction, until the user releases the lock to allow retraction. As another example, the lock may comprise a releasable clamp, wherein a user may pull on one portion of the cable segment 6, causing the portion to extend from its corresponding aperture 26, 28, and then clamp the cable segment 6 in the extended configuration into the clamp. When the user is finished using the cable retractor 2, he may then release the clamp and allow the biasing device's bias or tension to pull the cable segment 6 back into the retracted configuration. As another example, the lock may be of the type used in rolling window shades, or used in the well known circular cable retractors, wherein a user pulls once on the cable segment 6 to extend and subsequently lock the cable segment 6 in an extended configuration, and then pulls on the cable segment 6 again to unlock the lock and allow the cable segment 6 to retract into the retracted configuration. The lock could be either discrete or continuous. A discrete lock locks the cable segment 6 at one or more discrete extensions, while a continuous lock may lock the cable segment 6 at virtually any possible extension. The lock may be configured to temporarily inhibit movement of either portion 22, 24 of the cable segment 6 in the −α direction with respect to the base 4, or to temporarily inhibit movement of the sliding plate 14 in the −α direction with respect to the base 4. In one embodiment, where at least one of the guides 8, 10, 12 are rotatably affixed wheels, the lock could inhibit the rotation of at least one such wheel, thus inhbiting the cable segment 6 from moving about that one or more wheel.

In one embodiment, the sliding plate 14 and guides 10, 12 are oriented such that a line substantially passing through centers of the guides 10, 12 is substantially parallel to direction α. An advantage to this feature is that it may be possible to manufacture the cable retractor 2 with relatively small dimensions relative to diameters of the guides 10, 12 to minimize size. However, it is not a limitation that the aforementioned line is substantially parallel to direction α. In various embodiments the line could be perpendicular to direction α or at an angle to direction α.

In the embodiment shown in FIG. 1, where the line is substantially parallel to direction α, guide. 10 may have a larger diameter than guide 12 to prevent contact by adjacent threaded portions of the cable segment 6. Alternatively or in addition, a distance between guides 10, 12 may be increased. The longer the cable retractor 2 is made, the more acute the angle subtended by the cable segment 6 in wrapping around guide 10. Various design choices are available to help prevent undesired contact by adjacent portions of the cable segment 6, depending upon the particular application of the invention.

In one embodiment, a sliding plate 14 need not be used at all, such as where each of guides 10, 12 is independently movable (translationally or otherwise) in direction α against a bias or tension provided by one biasing device 20 for each guide 10, 12. Further, sliding plate 14 may connect more than two guides. In another embodiment, guide 8 may not be fixed to base 4, and may be independently movable (translationally or otherwise) relative to the base 4 via a biasing device (not shown) connecting the guide 8 to base 4. In another embodiment, more than one sliding plate 14 may be used, each sliding plate independently connecting at least two guides.

In operation, a user chooses which portion 22, 24 (or both) to extend, and then pulls on that portion of the cable segment 6. One end of the cable segment 6 may be connected to an electrical device (any device known in the art to or from which electrical information and/or power may be transferred), while the other end may be connected to another electrical device and/or plug or connector (not shown) configured to allow that end to be connected to another electrical device. Electrical plugs and connectors are well known in the art. Alternatively, both ends of the cable 6 may be connected to electrical plugs/connectors, so that the cable retractor 2 serves as an extendible adaptor or extension cord. Then, when the desired extension length is reached, the user may lock the cable retractor 2 in its extended configuration (or the cable retractor 2 may automatically lock) by locking the cable segment 6 and/or the sliding plate 14. In extending the cable segment 6, the sliding plate 14 translationally moves relative to the base 4 along the track 18, and wheels (if any) of guides 8, 10, 12 rotate as the cable segment 6 moves relative to them. The bias or tension of the biasing device 20 and/or the stops 30, 32 maintains the cable segment 6 stretched and relatively tight, so as to prevent tangling and/or contact between different regions of the cable segment 6.

When the user prefers to retract the cable segment 6, she unlocks the lock of the cable retractor 2, thus allowing the bias of the biasing device 20 to pull the sliding track 14 away from apertures 26, 28, and causing the first and second portions 22, 24 of cable segment 6 to retract. First and second portions 22, 24 may each comprise a stop 30, 32, notch or other component configured to prevent too much of cable segment 6 from entering apertures 26, 28 and thus causing slack of cable segment 6 to build up.

In one embodiment, all of the guides 8, 10, 12 are coplanar, thus they cause the first and second portions 22, 24 of cable segment 6 to lie generally within a single plane when the device 2 is in the retracted configuration.

Turning now to FIG. 2, a cable retractor 52 according to another embodiment comprises a housing 54, a cable segment 56 comprising portions 94, 96, passing through an aperture 60 of the housing 54, stops 58, 59, sliding plates 62, 64, 66 translationally slidable in a direction β, γ, δ, along tracks 82, 86, 90, respectively, and guides 68, 70, 72, 74, 76, 78, 80. Sliding plate 62 connects guides 68, 70, sliding plate 64 connects guides 72, 74, and sliding plate 66 connects guides 76, 78. Each track 82, 86, 90 comprises a respective biasing device 84, 88, 92—which may or may not be located within the respective track 82, 86, 90—that provides a bias or force in a direction substantially away from aperture 60. As shown in FIG. 2, the cable segment 6 is threaded through aperture 60, around guide 68, around guide 72, around guide 76, around guide 80, around guide 78, around guide 74, around guide 70, and through aperture 60 such that the stops 58 are located on the side of the aperture 60 away from the guides 68 and 70. Housing 54 comprises a plurality of walls, such as six (in the case of a parallelepiped), including a base to which the sliding plates 62, 64, 66 are movably connected. In one embodiment, the sliding plates 62, 64, 66 are movably connected to only and exactly one wall of the housing 54. This feature provides the advantage of reduced complexity and manufacturing cost, as only one set of tracks 82, 86, 90 must be formed in the housing 54. In one embodiment, cable segment 56 comprises a ribbon cable, comprising a plurality of wires connected so as to form a substantially flat ribbon, as understood by one of ordinary skill in the art.

In operation, a tension may be applied to one portion 94 (or 96) of the cable segment 56 to pull the portion 94 (or 96) generally in a direction β to thereby move a length, causing the sliding plates 62, 64, 66 to move in corresponding directions β, γ, δ (as shown) by distances (that are each less than the length) against the biases or forces of the biasing devices 84, 88, 92. As the portion 94 (or 96) is pulled, cable segment 56 moves relative to the housing 52 and relative to guides 68, 70, 72, 74, 76, 78, 80. The portion 94 (or 96) may be pulled a maximum distance, corresponding to the full ranges of motion of the sliding plates 62, 64, 66 and/or biasing devices 84, 88, 92. As shown, either or both portions 94, 96 may be pulled from the housing 54 in direction β. In a fully retracted configuration, stops 58 are in contact with aperture 60, and the biases or forces of the biasing devices 84, 88, 92 prevent slack of cable segment 56. The aperture 60 may comprise a single hole in a same wall of the housing 54, or may comprise two holes in the same or different walls of the housing 54. As discussed above, a lock may be used to maintain the cable retractor 52 in an extended configuration, until it is released, allowing the cable segment 56 to retract back into housing 54 under the force of the biasing devices 84, 88, 92.

In one embodiment, housing 54 comprises a base wall 53 and a substantially coplanar top (not shown) separated from the base wall 53 by a width. The base wall 53 comprises the tracks 82, 86, 90, which may comprise elongated openings through which guidepins pass and therefore slidably connect the sliding plates 62, 64, 66 to the housing 54. Each guidepin may comprise a head having a diameter larger than a width of its corresponding track 82, 86, 90, and a shaft having a diameter smaller than the width of its corresponding track 82, 86, 90, so that the sliding plates 62, 64, 66 are slidably connected to the housing 54. In one embodiment, only the base wall 53, and not the top, comprises the tracks 82, 86, 90. In another embodiment, both the base wall 53 and the top may comprise tracks along which the sliding plates 62, 64, 66 translationally slide with respect to housing 54 and through which the sliding plates 62, 64, 66 connect to the housing 54. The guidepins and/or tracks 82, 86, 90 may comprise and/or be coated with a low-friction material or composition to reduce moving friction of the sliding plates 62, 64, 66 along the tracks 82, 86, 90.

In one embodiment, the cable retractor 52 is configured to prevent dislodging of the cable segment 56. For example, the width between the first and second side walls may be sufficiently small relative to the diameter of the cable segment 56 to prevent the cable segment 56 from dislodging from the guides and falling into a gap between the side walls and the guides. Further, the guides may have a width sufficiently large relative to (e.g., greater than) the diameter of the cable segment 56 (or width of the cable segment 56 in the case of a ribbon). Alternatively or in addition to the first and second side walls maintaining the cable segment 56 on the guides, one or more of the guides may comprise a lip or retaining element (not shown) that enshrouds the cable segment 56 to prevent the cable segment 56 from dislodging or falling off of the guide.

Turning now to FIG. 3, an electronic device 100 comprises a housing 101 formed from walls 103, 104, 105, 106, top 107 and bottom 108, two speaker elements 102, are affixed to openings in wall 104. An automatic cable retracting system 109 is formed within the housing 101.

The cable retracting system 109 comprises a cable segment 110, upper guides 120, 121 and lower guides 122 and 123 suspended within the housing 101. In one embodiment, biasing devices 114 movably suspend upper guides 120, 121, within the housing 101, biasing or tensioning the cable segment 110, while lower guides 122, 123 are affixed to wall 103. The cable segment 110 is threaded through aperture 118 in wall 106, around each of the four guides 120, 121, 122, 123, and affixed to the housing 101 by strain relief connection 116. Any of the features and/or variations discussed with respect to corresponding elements and functions shown in FIGS. 1 and 2 may be applied to those of FIG. 3.

Cable segment 110 comprises an electric cable connected to the electronic device 100 and configured to transfer power and/or information to and/or from the electronic device 100. The guides 120, 121, 122, 123 may comprise, e.g., wheels rotatable about axes and/or nonrotatable guidepins having a low-friction material or substance to minimize rolling and/or sliding friction. In one embodiment, guide 120 is also translationally movable relative to the housing 101.

In operation, a user may pull on the free end of the cable segment 110 to cause the cable segment 110 to extend from the housing 101 against the biases or tensions of biasing devices 114. The cable segment 110 may then be locked (manually by the user or automatically) in the extended configuration while using the extended cable segment 110. When ready to retract the cable segment 110, the user may disengage the lock on the cable segment 110, thus allowing the force of biasing devices 114 to retract the cable segment 110 back into housing 101. The electric cable segment 110 may include a plug or any other known mating device to allow the cable segment 110 to be electrically connected to another device to allow information and/or power to pass through the cable segment 110.

Turning now to FIG. 4, an automatic cable retracting system 152 comprises a housing 154, an USB cable 156 having USB plug ends 162, guides 158 suspended within the housing via biasing devices 160 that provide a bias or tension on the guides 158, and USB plugs 162 connected to ends of the cable segment 156. The cable segment 156 passes from one USB plug 162 through an aperture in the housing 154, around both guides 158, through a generally opposing aperture in the housing 154, and to the opposing USB plug 162. In operation, a user may use the cable retractor 152 as a USB extension cord by pulling on one or both USB plugs 162 against the bias or tension of biasing devices 160 to extend the cable segment 156 from the housing 154. As described with respect to the other Figures above, the retracting system 152 may or may not lock cable 156 in an extended configuration through the use of a locking mechanism (not shown).

Turning now to FIG. 5, a mouse 202 comprises a mousing unit 204 connected to a plug 208, such as a USB plug, via an automatic cable retracting system 206, according to any embodiment described herein, utilizing an electric cable 210. Turning now to FIG. 6, a keyboard 252 comprises a keyboard unit 254 connected to a plug 258, such as a USB plug, via an automatic cable retracting system 256, according to any embodiment described herein, utilizing an electric cable 260.

Other embodiments of the present invention will be described below. The invention may be a linear cable retracting mechanism that can be located either centrally on a cable or at one end, with no performance disadvantage in either condition. When installed or built directly into the housing of a product, one end of the cable may be permanently attached to the product through direct electrical connection of the wires in the cables (either soldered to a printed circuit board or via a connector). The cable may be routed within the housing around a moving pulley system that provides the mechanical advantage necessary to permit retraction of a cable that is longer than the length of the housing in which the cable is stored. The mechanical advantage may be modified by changing the number of pulleys or moving parts within the system. In one implementation, three total pulleys are used, with two of them mounted in close proximity on a moving sled (or sliding plate). The sled is attached to a biasing device so that as the cable is extended, the sled moves forward and increases the tension on the biasing device. The biasing device may be of any type that provides sufficient force to retract the cable and sufficient travel to permit full extension of the cable. The system may be modified to employ two or more moving sleds with one or more pulleys attached to each sled. In the case where multiple sleds are used, proper tensioning of the biasing device may be required for each sled to return the sled to the rest position and thereby retract the cable routed through the associated pulleys. Such an implementation can provide one or more of the following advantages. The motion is linear, permitting the possibility of a narrower profile for the retracting mechanism than could be accomplished with a rotary mechanism. The mechanism requires no moving electrical components (brushes or wipers) so electrical noise generation is minimized and there are no contacts to wear out. The cable routing approach employed may be such that the cable does not cross over itself in the enclosure, allowing for a low profile mechanism. The mechanism may be built into a stand-alone housing, or may be built directly into the enclosure of the main product. The alignment of the sled in one implementation minimizes non-linear motion, thereby reducing the tendency of the mechanism to bind up as it travels. The mechanism can be simple enough to permit it to be built for low cost applications. A single retractor design can be employed for internal solutions as well as in-line cable solutions. The length of available cable in the application/use is related to the linear size of the mechanism and the number of pulleys employed.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. For example, each of the cable segments has been described with reference to electrical cables, such as audio or other data/information or power cables. However, the invention is not limited thereto. The cable segments may comprise any linear medium, such as fiber optic cables, hoses (e.g., for medical devices, garden hoses, or other plumbing applications), ropes, measuring devices, straps, and others. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. An automatic cable retracting system, comprising: a base; a guide translationally movable along a line parallel to a surface of the base; a biasing device for resisting movement of the guide, in a direction along the line, over a range of motion; and a cable having a middle section and a first and second end of the middle section, a portion of the middle section being in contact with and changing direction around the guide, wherein the system is configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion, wherein the length moved by the first end as a result of the tension is greater than the distance moved by the guide as a result of the tension, and wherein no portion of the cable is permanently affixed to the base.
 2. The automatic cable retracting system as claimed in claim 1, wherein the system is configured so that a second tension on the second end causes the second end to move a second length, and causes the guide to move a second distance of at least a portion of the range of motion, and wherein the second length moved by the second end as a result of the second tension is greater than the second distance moved by the guide as a result of the second tension.
 3. The automatic cable retracting system as claimed in claim 1, wherein the system comprises at least three guides, wherein at least two of the at least three guides are translationally movable along the direction relative to the base.
 4. The automatic cable retracting system as claimed in claim 3, wherein all of the at least three guides are translationally movable along the direction relative to the base.
 5. The automatic cable retracting system as claimed in claim 1, wherein the cable comprises an electric cable.
 6. The automatic cable retracting system as claimed in claim 1, wherein the system comprises: a plurality of guides; and a sliding plate connecting at least two of the plurality of guides, wherein the sliding plate is slidably connected to the base.
 7. The automatic cable retracting system as claimed in claim 6, wherein the sliding plate is oriented relative to the base so that a line passing through centers of the at least two of the plurality of guides is substantially parallel to the direction.
 8. The automatic cable retracting system as claimed in claim 6, wherein a first one of the at least two of the plurality of guides connected to the sliding plate is larger than a second two of the at least two of the plurality of guides.
 9. The automatic cable retracting system as claimed in claim 1, wherein the base comprises a printed circuit board.
 10. The automatic cable retracting system as claimed in claim 1, wherein the system comprises a plurality of guides, and wherein at least one of the plurality of guides is not rotatable relative to the base.
 11. The automatic cable retracting system as claimed in claim 1, wherein the system comprises: a housing having a plurality of walls including the base; and an odd number of guides, wherein opposing portions of the cable pass through a same wall of the housing.
 12. The automatic cable retracting system as claimed in claim 1, wherein the guide comprises a wheel rotatable about an axis connected to the base.
 13. The automatic cable retracting system as claimed in claim 1, wherein the length moved by the first end as a result of the tension is greater than three times the distance moved by the guide as a result of the tension.
 14. An electronic device, comprising: an electronic unit; and the automatic cable retracting system as claimed in 1, the system formed within the unit, wherein the cable comprises an electric cable, and wherein the electric cable is configured to transfer power or signals to or from the unit.
 15. The automatic cable retracting system as claimed in claim 14, wherein the electronic unit comprises a speaker.
 16. The automatic cable retracting system as claimed in claim 14, wherein the electronic unit comprises a keyboard.
 17. The automatic cable retracting system as claimed in claim 14, wherein the electronic unit comprises a computer mouse.
 18. An automatic cable retracting system, comprising: a base; two movable guides, the guides being translationally movable along a direction relative to the base; biasing device for resisting movement of the two guides, in the direction, over a range of motion; and a cable having a middle section and a first and second end of the middle section, a portion of the middle section being in contact with and changing direction around the two guides, wherein the system is configured so that a tension on the first end causes the first end to move a length, and causes at least one of the two guides to move a distance of at least a portion of the range of motion, and wherein the length moved by the first end as a result of the tension is greater than the distance moved by the at least one of the two guides as a result of the tension.
 19. The automatic cable retracting system as claimed in claim 18, wherein the system comprises at least three guides.
 20. The automatic cable retracting system as claimed in claim 18, wherein the cable comprises an electric cable.
 21. The automatic cable retracting system as claimed in claim 18, further comprising a sliding plate connecting the two guides, wherein the sliding plate is slidably connected to the base.
 22. The automatic cable retracting system as claimed in claim 21, wherein the sliding plate is oriented relative to the base so that a line passing through centers of the two guides is substantially parallel to the direction.
 23. The automatic cable retracting system as claimed in claim 21, wherein a first one of the two guides connected to the sliding plate is larger than a second one of the two guides.
 24. The automatic cable retracting system as claimed in claim 18, wherein the base comprises a printed circuit board.
 25. The automatic cable retracting system as claimed in claim 18, wherein at least a first one of the two guides is not rotatable relative to the housing.
 26. The automatic cable retracting system as claimed in claim 18, wherein the system comprises: a housing having a plurality of walls including the base; and an odd number of guides, wherein opposing portions of the cable pass through a same wall of the housing.
 27. The automatic cable retracting system as claimed in claim 18, wherein at least a first one of the two guides comprises a wheel rotatable about an axis connected to the base.
 28. An electronic device, comprising: an electronic unit; and the automatic cable retracting system as claimed in 18, the system formed within the unit, wherein the cable comprises an electric cable, and wherein the electric cable is configured to transfer electrical power or signals to or from the unit.
 29. The automatic cable retracting system as claimed in claim 28, wherein the electronic unit comprises a speaker.
 30. The automatic cable retracting system as claimed in claim 28, wherein the electronic unit comprises a computer mouse or keyboard.
 31. An automatic cable retracting system, comprising: a housing; a guide translationally movable along a direction relative to the housing; a biasing device for resisting movement of the guide, along the direction, over a range of motion; and, a cable having a middle section and a first and second end of the middle section, a portion of the middle section being in contact with and changing direction around the guide, wherein the system is configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion, wherein the length moved by the first end as a result of the tension is greater than the distance moved by the guide as a result of the tension, and wherein exactly one wall of the housing comprises a track along which the guide is movable.
 32. The automatic cable retracting system as claimed in claim 31, wherein the track comprises an elongated opening in the exactly one wall, and wherein the system further comprises a connector slidably movable along the elongated opening and connecting the guide to the housing.
 33. The automatic cable retracting system as claimed in claim 31, wherein the cable comprises an electric cable.
 34. The automatic cable retracting system as claimed in claim 31, wherein the guide comprises a plurality of guides, and wherein the system comprises a sliding plate connecting at least two of the plurality of guides, the sliding plate being slidably connected to the housing.
 35. The automatic cable retracting system as claimed in claim 34, wherein the sliding plate is oriented relative to the housing so that a line passing through centers of the at least two guides is substantially parallel to the direction.
 36. The automatic cable retracting system as claimed in claim 34, wherein a first one of the at least two guides connected to the sliding plate is larger than a second one of the at least two guides.
 37. The automatic cable retracting system as claimed in claim 31, wherein the housing comprises a printed circuit board.
 38. The automatic cable retracting system as claimed in claim 31, wherein the system comprises a plurality of guides, and wherein at least one of the plurality of guides is not rotatable relative to the housing.
 39. The automatic cable retracting system as claimed in claim 31, wherein the system comprises an odd number of guides, and wherein opposing portions of the cable pass through a same wall of the housing.
 40. The automatic cable retracting system as claimed in claim 31, wherein the system comprises a plurality of guides and wherein at least one of the plurality of guides comprises a wheel rotatable about an axis connected to the housing.
 41. An electronic device, comprising: an electronic unit; and the automatic cable retracting system as claimed in 31, the system formed within the unit, wherein the cable comprises an electric cable, and wherein the electric cable is configured to transfer power or signals to or from the unit.
 42. The automatic cable retracting system as claimed in claim 41, wherein the electronic unit comprises a speaker.
 43. The automatic cable retracting system as claimed in claim 41, wherein the electronic unit comprises a computer mouse or keyboard.
 44. An automatic cable retracting system, comprising: a housing; a guide translationally movable along a direction relative to the housing; a biasing device for resisting movement of the guide, in the direction, over a range of motion; and an electric cable having a middle section and a first and second end of the middle section, a portion of the middle section being in contact with and changing direction around the guide, wherein the system is configured so that a tension on the first end causes the first end to move a length, and causes the guide to move a distance of at least a portion of the range of motion, wherein the length moved by the first end as a result of the tension is greater than the distance moved by the guide as a result of the tension, and wherein all portions of the electric cable within the housing are substantially coplanar. 